Clamp



FIG. 1 is a front view of a clamp of the claimed design.

FIG. 2 is a left side view of the clamp.

FIG. 3 is a rear view of the clamp.

FIG. 4 is a right side view of the clamp.

FIG. 5 is a top view of the clamp; and,

FIG. 6 is a bottom view of the clamp. 

I claim the ornamental design for a clamp, as shown and described. 